Conventionally, there has been known, as methods for calculating a target parking position of a vehicle in a parking assist apparatus, a method in which a detection result is used as a result from detecting parking section lines using a camera (a parking section line recognition method), and a method in which a detection result is used as a result of detecting a space that allows parking using an ultrasonic sonar (a parking allowable space recognition method) (e.g., refer to Patent Documents 1 and 2).